This premium fuel, an 80 - 20 blend of isobutane and propane, boosts the performance of canister stoves. It outperforms standard butane - propane mixtures and burns clean to reduce soot and clogs. Our new 4 oz. canister has a smaller diameter for optimal fit inside the 1.0L Reactor® Stove System • Improved Performance: 80 - 20 blend of isobutane and propane delivers superior performance throughout the life of the canister and in colder temperatures. • Clean-Burning: Optimal fuel blend results in reduced soot and clogs. • Recyclable: Canisters can be recycled. Consult your local recycling center for regulations. • Volume: 3.9 oz / 110g